The present invention relates in general to automotive climate control systems, and, more specifically, to a system and method for monitoring of an automatic temperature control mode and adjusting performance or developing corrective actions in response to user actions that override automatic settings to the climate control.
Heating, ventilating, and air conditioning (HVAC) systems control the climate in transportation vehicles such as automobiles in order to maintain thermal comfort of the vehicle occupants. Typically, a variable-speed blower passes air through heat exchangers and delivers conditioned air to various locations within the passenger cabin. Warm air may be provided by a heater core receiving heat from coolant flowing in a combustion engine, for example. Cool air may be obtained from a conventional air conditioning system having a motor driven compressor and an evaporator.
The simplest climate control systems in motor vehicles provide the occupant with direct control of the intensity of heating or cooling, the operating speed of the blower, the relative amount of air flow going to different registers, and the ratio of fresh air to recirculated air. This requires the user to continually monitor and adjust the climate control settings in order to remain comfortable.
Automatic temperature control systems have also been introduced wherein a feedback control system monitors ambient air temperature within the passenger compartment and other locations and automatically adjusts blower speed, airflow settings, and heater core or air conditioning operation to maintain a desired temperature setting. In some vehicles, multiple zones have been implemented with separate automatic temperature control with individual target temperature settings to being made for each zone.
A typical electronic automatic temperature control (EATC) system allows the user of the HVAC to select either manual control or an automatic control (Auto) mode. When Auto mode is selected, the EATC software utilizes numerous inputs to determine settings for the various outputs in order to maintain a user-specified temperature setpoint. In the event that the user desires an HVAC performance different from the settings made by Auto mode, the user interface continues to monitor for a user control action such as a button press to override one or more of the output settings and/or to change the temperature setpoint.
Sophisticated algorithms have been developed to help ensure that Auto mode properly responds to changing environmental and other conditions such as outside and inside temperatures, humidity, and sun load in order to provide thermal comfort for the occupants. Developing appropriate control algorithms (i.e., models) that are satisfactory to all typical users for each different model of vehicle is a complex task. Testing of the control system under every potential combination of conditions may be impractical or overly expensive. Moreover, user acceptance or non-acceptance of performance of a particular algorithm can only be discovered in general terms through surveys, warranty actions, or other broad characterizations. Thus, it would be desirable to better monitor user interaction with automatic controls.